Put 1 pint water on to boil and add sugar, stirring until completely dissolved. Set aside in sterilized jar for later use. Meanwhile, wash and scrub the parsnips, slice them thinly, peel and slice the bananas, and place all in saucepan with 6 pints water. Bring to low boil for 30 minutes. Strain off liquid into primary and leave to settle. After 24 hours, siphon the clear liquid off the sediment into secondary. Add grape concentrate, tartaric acid, pectic enzyme, tannin, and yeast nutrient. Stir to mix and add activated wine yeast. Cover secondary. When fermentation is vigorous, add sugar-water and flowers or rose petals and fit airlock. After 1 week, strain off flowers and return liquid to clean secondary. Refit airlock and ferment until wine begins clearing. Rack, top up and refit airlock. When wine is completely clear, rack again and add 2 crushed Campden tablets dissolved in 1/2 cup water, top up and refit airlock. After 2 weeks, rack again and add 2 more crushed Campden tablets dissolved in 1/2 cup water. Sweeten with sugar-water to specific gravity 1.008, top up and refit airlock. Check airlock periodically and rack every 6 months for 18 months. Rack into bottles and store additional 6 months.